In the field of printing technology, non impact printing methods such as inkjet printing may be used to deposit an ink composition onto print media to form an image. An ink composition typically comprises a colourant material and a vehicle, such as an aqueous solution, for delivering the colourant material to the print media. A wide range of such ink compositions is known in the industry. It is also known to use various pre-treatment compositions in combination with ink compositions in order to enhance the quality of a final image. Pre-treatment compositions are often substantially colourless liquid compositions that interact with elements of the ink composition to fix colourant to the print media. Pre-treatment compositions may help to improve image quality for example by reducing image bleeding, edge roughness and other image quality issues.